1. Field of the Invention
Moving medium magnetic recording devices universally employ a wound magnetic core having a flux gap in the flux path to write and read data in the medium. In the high density devices employed today it is important that the reluctance of the flux gap and of the flux path in general be precisely controlled to provide maximum accuracy in performing the data transducing operations. It is further desirable to reduce the reluctance of the remainder of the flux path as much as possible for increased readback voltage and lower writing current. Complicating all these problems is the fact that the high data densities common today require extremely small dimensions of the core flux gap and hence at least one of the elements from which the core is formed must have these very small dimensions. In a design in popular use today, a relatively large "I" element is bonded to a relatively small "C" element to form the flux gap and flux path. Because the relatively small C element defines these flux gap dimensions, control of flux gap depth within desired limits has been difficult.
2. Description of the Prior Art
Prior techniques have all involved formation of the C element with the desired flux gap depth and then correctly positioning it on the face of the I element. The depth of the C element then forms the smaller depth dimension of the flux gap. A variation on this technique involves initially forming the C element with the flux gap depth dimension greater than desired, and bonding the C element to the I element with less accurate placement than required by the aforementioned technique, and then machining the transducing surface formed by the I and C elements until the C element flux gap face depth equals that desired for the less deep flux gap face. This is also not preferred because the relative smallness of the C element makes creation and use of a reference surface on it quite difficult. This latter method is shown by U.S. Pat. Nos. 3,402,463 (Bos et al.) and 3,395,451 (Peloschek). Other patents directed toward producing magnetic heads having exactly dimensioned gap depths are U.S. Pat. Nos. 3,094,772 and 3,302,268 (both Duinker) and 3,435,155 and 3,531,859 (both Van Der Voo). U.S. Pat. No. 3,550,264 (Bouwma) discloses a method which employs a mandrel or dowel inserted in the core aperture to provide a reference surface for measuring gap depth. All the techniques described in these patents are relatively straight forward and direct. But when dealing with extremely small gap depths they are difficult to employ and are not sufficiently accurate.